1. Field of the Invention
The present invention generally relates to a disk recovery method, in particular, to a method for recovering video data in a disk when an error occurs during a disk reading process.
2. Description of Related Art
Along with the coming of the information era and the increasing quantity of digital data of various sources and formats, optical storage medium has become one of the most indispensable tools because of its characteristics such as large storage capacity, fast access speed, high portability, and easy storage.
Digital versatile disk (DVD) is a new generation optical information storage medium. A DVD offers much higher data density and capacity than a conventional compact disk (CD), and a DVD could be in a format of DVD-ROM, DVD-R, DVD-RW, DVD-RAM, DVD+R, or DVD+RW according to the application and manufacturer thereof. A user can easily record videos or data into a DVD by using a DVD burner installed in a computer system or a DVD recorder.
However, while recording a video into a disk, the video recording process may be terminated due to bad disk quality, disk defects caused by improper usage (for example, scratches or fingerprints), or an unexpected power failure during the video recording process. In this case, the video data recorded into the disk before the problem occurs becomes inaccessible.
To be specific, during video recording, the processing of a file system in a disk is different from that in a recording software. Except that the address of an initial file system is fixed when the disk is just initialized, the address of a file system is always determined according to the end address of a video chapter actually recorded into the disk before the disk is finalized. If the disk is used for recording another video next time, a data detection operation is first performed in order to obtain the file system last recorded into the disk, and the video is then recorded into the disk or the disk is finalized according to the data of this file system.
FIG. 1 is a diagram illustrating the data in a conventional write-once DVD. Referring to FIG. 1, when the write-once DVD is used for recording a video, whenever a video chapter (video chapter 110 or 120) is recorded, a file system (file system 130 or 140) is established after the end address of the video chapter for recording the related information of the video chapter so that later on the video chapter can be read and played by a DVD player/recorder.
However, while recording a video into a disk, the length of the video is usually determined by a user. Accordingly, the lengths and number of videos recorded in a disk are not confirmed before the disk is finalized. If an error occurs during a video recording process, the video recording process cannot be ended normally and accordingly the file system in the disk cannot be updated in time. As a result, the disk cannot be used for recording other videos and even the videos recorded in the disk before the error occurs cannot be recovered.